Skill Development/Guided Practice: Students will be able to explain and diagram the phases1 of the cell cycle. 1 Phases - The steps in a process. Concept Development: The cell cycle describes the growth, development, and reproduction of a cell. Skill Development/Guided Practice: 2Replicate – make an identical copy The Cell Cycle: You’ll spend most of your life growing and developing. Only a small portion of a human’s life cycle is spent in the reproductive phase1. The same is true for cells. The cell cycle describes the growth, development, and reproduction of a cell. The phases1 of the cell cycle are: interphase, mitosis, and cytokinesis. Interphase: A cell performs specific functions during interphase. During interphase, the chromosomes in the nucleus are like a bunch of thin spaghetti noodles. Each chromosome is so thin that it cannnot be observed with a light microscope. The three phases1 of interphase are G1, S and G2. During G1 phase, a cell grows and carries out its usual cellular functions. For example muscle cells are using oxygen and glucose to produce ATP necessary for your body to move. Growth continues into S phase1. During S, the chromosomes inside a cell’s nucleus replicate2. The copies of a chromosome made during S phase1 are called sister chromatids. Sister chromatids are held together at a region near the middle of each chromatid called the centromere. The replication2 of chromosomes during S phase1 ensures that the two new cells formed by cell division are identical. A cell continues to grow and carry out cellular functions during the final G2 phase1. It also replicates2 organelles during this phase1 of interphase.

Phases of Mitosis States Shared Relevance: Skill Development/Guided Practice: 1Phases – The steps in a process 2Replicate - make an identical copy Phases of Mitosis Prophase: The first phase1 of mitosis is prophase. Two major events happen during prophase. First, the DNA that makes up a replicated2 chromosome twists into tight coils. The other major event during prophase is that the membrane around the nucleus breaks apart. Metaphase: During the second phase1 of mitosis, metaphase, the replicated2 chromosomes move to the middle of the cell . The pairs of sister chromatids line up end to end across the center of the cell. Hair-like spindle fibers pull and push the chromosomes to the middle of the cell. Anaphase: In the third phase1, anaphase, the sister chromatids of each replicated2 chromosome begin to separate. The spindle fibers pull the centromere apart and chromatids move away from each other, toward opposite ends of the cell. Now the chromatids are called chromosomes. Telophase: The final phase1 of mitosis is telophase. During telophase, a new membrane forms around each set of chromosomes. The chromosomes become less tightly coiled. At the end of telophase, there are two new nuclei that are identical to each other and the original nucleus. However the cell has not divided. States Why do some powers belong only to the states? 19. The Constitution was written to limit the power of the federal government. 20. The Constitution does not spell out specific power of the states because the writers of the Constitution wanted the states to keep some sovereignty. 21. So, it says that the states retain, or keep, any powers that are not given to the national government. 22. For instance, the Constitution says nothing about schools, marriage, establishing local governments, owning property,licensing doctors and lawyers, or most crimes. 23. The states make the laws in these areas of life. 24. The Constitution does, however, outline the responsibilities of states to each other. Article IV says that each state must give “full Faith and Credit”1 to the laws and court decisions of other states. 25. This means accepting other states’ laws and court decisions as legal. 26. For example, a driver’s license issued in one state is legal in every state. 27. Similarly, states must obey legal contracts that people have made in other states. 28. Like the commerce clause, the full faith and credit provision brings stability to business dealings.29. States are also required to help each other track down fleeing criminals.30.Criminals cannot escape justice by fleeing to another state. 31. Finally, the Constitution does not allow one state to discriminate2 unreasonably against a citizen of another state. 32. A state may not, for example, refuse to let a child who was born in another state attend its public schools. 1 must recognize it 2 to treat differently Cytokinesis: Cytokinesis is the final phase1 of cell division. During cytokinesis, the cytoplasm and its components divide to form two identical cells called daughter cells. During cytokinesis the cell membrane squeezes inward similar to squeezing the middle of a balloon. Shared Why are some powers shared? 33. Federal and state governments also share some powers because there are powers both groups need to function. 34. Combined, the federal and state governments share power because it is easier to do things like raise taxes for public projects. 35. Also, both levels of government can build roads, borrow money, and regulate education. 36. If you think the sharing of power, sounds complicated, you are right. 37. Consider presidential elections. Congress sets the date for national elections, while the states register voters and run the elections. 38. States count the ballots, while the national government organizes the Electoral College vote, which determines who will be president. 39. Federalism is also complicated because the Constitution provides only a general framework for the sharing of powers. 40. There was no way for the framers to spell out rules for every possible situation. 41. The federal system continues to evolve through new laws, court decisions, and constitutional amendments. Relevance: 1- Understanding mitosis provides us with a mechanism (the how) behind organisms evolving from unicellular to multicellular organisms. 2- Understanding mitosis provides a foundation for meiosis (next lesson). 3- Science jokes are awesome!

Use the guide below to draw each phase of cellular reproduction Use the guide below to draw each phase of cellular reproduction. Draw a box around and label the steps that together make up mitosis. 2) What are the 3 phases of the cell cycle? 3) Why is it important that the DNA replicates during interphase? 4) Explain what happens during each phase of cellular reproduction. Interphase: Prophase: Metaphase: Anaphase: Telophase: Cytokinesis: How is mitosis different from cytokinesis? If cytokinesis failed to happen what would be the outcome for the cell?

Closure / Exit Ticket: In your own words, explain why cellular reproduction is important to organisms.

Do Not Print For Students Delivery Strategies Legend – Consider putting these symbols as reminders to use the strategies at first. You can delete them as you get used to the pattern of the delivery. Word Transfer Ex. “When I say determine, you say figure out. When I say figure out, you say determine” T Teacher pre-reads S Students read T/S Teacher and Students read PS Pair Share on a higher order question NV<3> Non-volunteer, about 3 students V Take a Volunteer PS<SF> Pair Share on a higher order question and give them a sentence frame CFU Ask a higher order question to check for understanding (in the Skill Development) Asking a process question may not be necessary WB Students use a whiteboard for short response